Railway grade crossing construction



May 12, 1931. e. R. BURKHARDT ET AL 34 RAILWAY GRADE CROSSING CONSTRUCTION Filed Aug. 12, 1929 2 Sheets-Sheet 1 INVENTORS GEOR. BURKHARDT' CHARLES vv. BREED y 1931- G. R. BURKHARDT ET AL 1,805,234

RAILWAY GRADE CROSSING- CONSTRUCTION Filed Aug. 12, 1929 2 Sheets-Shee 2 INVENTORS CHARLES w BREED GEQR. BURKHARDT BY Qua 12M;

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Patented May 12, 1931 TTES GEORGE R. IBURKHARDT, OF CHICAGO, AND CHARLES W. BREED, OF WESTERN SPRINGS,

ILLINOIS RAILWAY GRADE CROSSING CON STRUGTION Application filed. August 12, 1929. Serial No. 385,135.

This invention relates to the sectional metallic road bed which is used between and adjacent the railsof a railway track where a road crosses a track at grade; and its object is to provide a section or element which shall be of maximum strength for its weight and shall also be of such simple design that it may be cheaply manufactured and installed. It consists of certain features and elements of construction as herein shown and described and as indicated by the claims. I

In the drawings Figure 1 is a partial plan view of a railway grade crossing employing sectional units or elements embodying this invention.

Figure 2 is a vertical section taken as indicated at line, 2-2, on Figure 1.

Figure 3 is a detail section taken as indicated at line, 3-3, on Figure 1.

Figure 4 is a top plan view of a railway crossing employing a modified form of the invention.

Figure 5 is a vertical section taken as indicated at line, 55, on Figure 4.

Figure 6 is a detail section as indicated at line 6-6 on Figure 4.

Referring first to Figure 1 the rails of the track are indicated at 1 with the usual cross ties at 2, to which said rails are secured by track spikes, 3, with the usual tie plates,

4, interposed to provide bearing surface. At one time it was customary to provide a road surface between the rails and beside them by merely laying heavy planks on the ties, 2. But with the increase of heavy trafiic which is principally automotive in nature, such crossings have been found inadequate and are being replaced by various constructions which promise greater durability. The road structure which is the subject of this invention consists of a plurality of rectangular metallic units, each providing a portion of the area of a roadway at the crossing. As shown in Figures 1, 2 and 3, each of the units, 5, is a casting of hollow or tubular formation with lateral flange portions, 6, extending from the tubular part to rest upon shim blocks, 7, which in turn rest upon the cross ties, 2, of the track. As seen in Figure 3, the cross-section of the tubular structure resembles a truss having a fiat upper chord which forms the road surface of the unit and a curved lower chord, whose distance from the upper chord varies from the deepest point of the truss at the middle to the ends of the truss which merge in the flanges, 6. The upper and lower chords are united permanently by a rib or spacer, 8, at the middle of the span, and to avoid superfluous weight both upper and lower chords may be formed with apertures or perforations, 9 and 10. These openings also serve to provide drainage and improve the tractive surface of the upper chord for road vehicles.

As may be seen from Figure 2, the edge of each unit, 5, adjacent the rail, 1, consists in a depressed flange, 11, which provides clearance for the wheel flanges of cars and en gines on the track, and which also engages under the head of the rail to hold down this edge of the road unit. The opposite edge, 12, stops short of the adjacent edge, 12, of the next unit and the adjacent units are wedged apart and at the same time held down by beveled blocks, 13, which overlap the adjacent corners of the edges, 12, each of said blocks, 13, being secured to the shim block, 7 by means of a lag screw, 14, whose head may be countersunk in a suitable recess in the block, 13. Thus, as will be evident from Figure 1, each of the blocks, 13, occurring between the rails, 1, 1, serves to secure the adjacent corners of four road units, 5. Outside the rails, similar but specially dimensioned units, 5 are employed to form approaches to the crossing and their adjacent edges are likewise held down by beveled blocks, 13.

At the lateral margins of the crossing modified units, 5 are employed, each having notches, 15, in the marginal flange, 6', to receive suitable lag screws, 16. Thus, if the track ties, 2, are carefully spaced, a crossing made up of these metallic units may be very quickly and easily installed in a manner which leaves little possibility for the units to work loose or get broken. However, if breakage should occur, the replacement of the damaged unit can be made in a few minutes time and without serious interference noted that, as shown, the employment ot the shim blocks, 7, provides for men ting the crossing units so that their upper surfaces come substantially at the height of the t rail of the track, thus providing a relativ smooth crossing for vehicle trailic iransvei ly of the rails, and to adapt the structure to railroads using (llildllllt weight and dunensions of traffic rails, it is only necessary to modify the height of the shim blocks employed.

Since practically all railroads new utilize the track rails, l, l, for an electric circuit controlling block signals and sometimes other apparatus, it is necessary to maintain electrical insulation between the two rails of the track; therefore, the beveled clamping block, 13, which secures the metallic road sections in place be insulated from them by interposing suitable material such vulcanized fiber, as indicated at 18, between use surfaces of the block, 13, and the parts of the road sections which it e1 Thi. is not necessary with the nail I where the road crosses only a single track, but, of course, it the metallic crossing extencs from one track to the other on a double track or multiple tra cl; line, the insulating expedient must be employed between adjacent road sections.

As may be seen from Figure 2, the cast tubular unit may be still further lightened by apertures, 17, in the spacing rib, 8, which ties together the upper and lower chords of the truss form.

Since for cast steel, of which this unit is intended to be made, it is customary to consider the material as of substantia ly the same strength in tension and comp ession, we have shown the cross section oi the upper and lower chords of the truss term in Figure 0 as substantially the same. Ant. since 1 any beam the horizontal increase from the interior planes to the surfaces at the upper and lower sides of the beam, our construction concentrates the material principally in. the upper and lower chordmlea f 1g only suflicient steel in the intermittent rib, 8, to properly tie together the upper and lower chords of the section so as to prevent collapse or distortion. ot the truss form under load. By this type 01 design we secure a road unit of maximum strength for the weight oi: metal. which it contains, and therefore the. such crossing units are made in large quantities, the tonnage is held to a minimum and the cost is kept proportionately low.

Figures l, 5 and 6 illustrate a modified structure in which plate steel is employed instead of cast steel, although the same general principles of design are observed as for the cast structure already described. The upper plate, 20, of each road section is substantially flat, while the lower plate, 21, is

bent downward and spaced therefrom. At their margins the two plates are secured together by rivets, 22, thus forming lodgment flanges which lie on the shim blocks, 7, in the same manner as the cast form already described. The middle portion of the lower plate, 21, may be parallel to the upper plate, 20, at 21, and the two plates are tied together by longer rivets, 23, which may be arranged in two rows staggered with respect to each other, and provided with spacing sleeves, 24, which definitely determine the depth o1 the beam thus formed. The road sections are secured to the shim blocks by lag screws or spikes, 25, and the heads of these screws, together with the protruding heads of the rivets, 22 and 23, provide suilicient roughness to give a good tractive surface as clearly seen in Figure 4:.

The road sections which are fitted between the two rails of the track are formed with depressed marginal portions providing flanged clearance grooves at 26, and as seen in Fig are at, these grooves are flared or widened at the margins of the crossing to ensure easy approaches for the wheel flanges. N0 insuators are required for this type of crossing as the truss sections may be so placed on the shim blocks, 7, as to avoid contact with each other or at least between sections which 9 are 111 contact with opposite rails of the track.

As indicated in Figure 4-, we may prefer to employ continuous spacing ribs, 24, in place oi the sleeves, 24, already described, and such spacing bars may be cast with suitable apertures, bosses, or widened portions to receive the rivets, 23. lVith either form of construction this fabricated plate type of road. section will frequently prove more economical than the cast type when it can be manufactured from small scrap pieces of odd sizes such as will accumulate in connection with the fabrication of larger plate structures such as girders and I-beams for bridge and building construction. The principles of design, however, are substantially the same for both embodiments of my invention and represent a method of securing maximum strength with a minimum weight of material for the particular purpose.

o claim 1. A metallic railroad crossing composed of substantially rectangular units arranged in rows parallel with the rails of the track, said units being tubular and having laterally extending flanges by which they are sup ported.

2. A metallic railroad crossing unit of tubular form disposed with the axis of said form perpendicular to the rails of the track.

3. A metallic railroad crossing unit having the form of a truss in vertical cross section with its upper and lower chords permanently united.

4. A metallic railroad crossing unit of tubular form arranged with the axis of such form substantially perpendicular to the rails of the track, the section of said unit in a vertical plane parallel to the said rails having the form of a truss with its upper and lower chords joined in flanges extending laterally of the tube form for supporting the unit.

5. A metallic railroad crossing unit tubular in vertical cross section parallel to the track and having the upper and lower walls of such tubular section united by a connecting portion extending across the tube.

6. A metallic railroad crossing composed of a plurality of substantially rectangular units, each tubular in section disposed with the axis of such tubular form perpendicular to the rails of the track and having laterally extending flanges and supporting blocks or shims resting upon the cross ties of the track and extending between the rails in position to receive said flanges of the crossing units.

7. A metallic railroad crossing unit of tubular form with supporting flanges extendingfrom the lateral walls of the tube and means extending through the tube uniting the upper and lower walls, whereby it acts as a truss.

8. A metallic railroad crossing unit composed of two plates secured together at two opposite edges and spaced apart intermediate such securement, thus forming a tubular member with laterally extending flanges, together with spacing means rigidly secured to both plates and extending through the space between them, whereby the plates constitute a truss adapted to be supported by said flanges. I

9. A metallic railroad crossing unit having the form of a truss in vertical cross-section, and shims by which said unit is supported at the ends of its truss form, said shims extending normal to the traffic rails, and each being super-imposed on one of the cross ties.

10. A metallic railroad crossing unit having the form of a truss in vertical crosssection, and shims extending normal to the traflic rails, and super-imposed on the cross ties of a railroad track for supporting said unit by lodgment of its ends on said shims, the shims and unit being dimensioned to bring the upper surface of the unit substantially level with the top of the traffic rail, and the truss form of the unit providing the greatest eiiective depth between said shims.

11. A metallic railroad crossing unit supported by shims extending normal to the traflic rails and super-imposed on the cross ties, a cross section of the unit adjacent a trafiic rail and normal thereto being of Z-form, and a cross section normal to the supports having its greatest efl'ective depth between them.

GEO. R. BURKHARDT. CHARLES W. BREED. 

